Means to prevent machine operation upon depression of plural keys



June 2, 1964 R J YOUNG 3,135,371

MEANS T0 PREVEN'i' MACHINE OPERATIONS UPON DEPRESSION OF PLURAL KEYS Filed March 18, 1963 4 Sheets-Sheet 1 FIG.I

INVENTOR RICHARD J. YOUNG ATTORNEY June 2, 1964 R. J. YOUNG 3,135,371

MEANS TO PREVENT MACHINE OPERATIONS UPON DEPRESSION OF PLURAL KEYS Filed March 18, 1965 4 Sheets-Sheet 2 FIG. 2-

J1me 1964 R. J. YOUNG 3,135,371

MEANS TO PREVENT MACHINE OPERATIONS UPON DEPRESSION OF PLURAL KEYS Filed March 18, 1963 4 Sheets-Sheet 5 FIG. 3

June 2, 1964 R. J. YOUNG MEANS TO PREVENT MACHINE OPERATIONS UPON DEPRESSION 0F PLURAL KEYS 4 Sheets-Sheet 4 Filed March 18, 1963 United States Patent MEANS TO PREVENT MACHINE OPERATION UPON DEPRESSION 0F PLURAL KEYS Richard J. Young, Lexington, Ky., assignor to International Business Machines (Iorporation, New York,

N.Y., a corporation of New York Filed Mar. 18, 1963, Ser. No. 265,717 6 Claims. (Cl. 197-16) This invention relates to key-operated machines, and more particularly to a control mechanism which prevents operation of a key-operatedmachine when more than one of the keys are depressed simultaneously.

There is shown in U.S. Patent 3,014,569, issued December 26, 1961 to L. E. Palmer, a typewriter having a plurality of perforated strips which are permitted to move under the control of keylevers for effecting an operation of a type head to print selected characters. When a single keylever is depressed, the type head operates to print a character corresponding to that keylever. If two or more keylevers should be depressed at the same time, the type head would still operate to print a character but it would not correspond to either of the keylevers. There is provided in the Palmer patent a single clutch which is engaged not only to release perforated strips or elongated elements for movement under control of a depressed keylever but also to position the type head for selecting a character and causing it to engage .a platen for printing the character. 1

This invention is directed to the use of a keyboard similar tothat of the Palmer patent but includes means which prevents operation of the machine when two or more keylevers are actuated simultaneously. There are provided in this case two clutches, one operating to release strips or slides for movement under the-control of a keylever, and the other operating, after testing the slides to determine that the proper combination was moved, for operating other mechanisms'to complete the functions of the machine. If the testing of the slides indicates than an improper combination moved, the second clutch is not engaged.

An object of this invention is to provide an improved mechanism for controlling the operation of a machine in response to the actuation of keylevers.

Another object is to provide in a machine which operates to produce functions corresponding to' any one of various keylevers actuated, an improved means for preventing operation of the machine when two or more keylevers are actuated simultaneously.

Other objects of the invention will be pointed out in the following description and claims and illustrated in the accompanying drawings, which disclose, by way of example, the principle of the invention and the best'mode, which has been contemplated, of applying that principle.

In the drawings:

FIG. 1 is a perspective view of an improved keyboard for a key-operated machine.

FIG. 2 is a perspective view of a mechanism which operates from the keyboard of FIG. 1 to type characters corresponding to the keylevers actuated.

FIG. 3 is a developed view of control elements or tapes used in the keyboard of FIG. 1.

FIG. 4 is a timing diagram of the various parts of the keyboard.

Referring to the drawings it will be noted that there is shown in FIG. 1 an improved keyboard which operates in response to the actuation of keylevers 1 for effecting operation of a mechanism shown in FIG. 2 to position a typehead 2 and print characters corresponding to the keylevers actuated. Instead of the mechanism for printing characters there could just as well be provided another mechanism operated from the keyboard to punch tape 3,135,371 Patented June 2, 1964 ice the interposer is an upwardly turned portion 7 against which a flat spring element 8 acts for urging the interposer rearwardly. Adjacent the forward end of the interposer is an upwardly projecting portion 10 adapted to latch over a cross bar 11 for holding the interposer in a forward position. A spring finger 12 acts against the lower side of the interposer for urging its forward end upwardly to a latched position. Projecting from the rear end of the interposer is a sensing finger 14 which is guided within an opening in a plate 15. Extending transversely of the keylevers at the rear side of the plate 15 are two groups of elongated elements or tapes 16 and 17 having openings at positions opposite each sensing finger 14 for receiving the latter when the interposer is moved rearwardly. As shown in FIG. 3, some of the openings 20 are long to permit movement of the tapes when a sensing finger extends through them and other openings 21 are just large enough to receive sensing fingers which hold the tapes against movement.

At the right hand ends of the tapes, as shown in FIG. 1, are openings 24 through which spring elements 25 extend for urging the tapes to the right. The openings 24 are formed as shown in FIG. 3 so that each spring element acts on only one tape and can move it to the right even through all of the other tapes are held against movement. All of the openings 20 and 21 at each character position are so formed that their right hand ends are in alignment. When any interposer 6 is unlatched from the plate 11 by depressing a keylever 1, the interposer is moved by the spring 8 to project its sensing finger 14 through all of the openings 20 and 21 in the tapes. If the tapes are then released for movement, each tape having a long opening 20 through which the sensing finger extends will be moved to the right by its spring element 25. Those tapes having small openings 21 through which the sensing finger extends will be held by the latter against movement. It will be noted in FIGJ3 that there are six code tapes 16 designated a to j and six check tapes 17 also designated a to f. The openings in each check tape are complements of the openings in the corresponding code tape. This means that a single sensing finger extending through openings in all of the tapes will permit some of the code tapes to move and hold the others against'movement. For the code tapes which are permitted to move, the corresponding check tapes are held against movement. The reverse is true for the code tapes which are held against movement, in which case the corresponding check tapes are permitted to move. If more than one keylever 1 was actuated and caused corresponding sensing fingers 14 to move through openings in the tapes, then there would always be one or more code tapes held while the corresponding check tapes were also held. This can be seen by assuming that sensing fingers extend through all of the tapes at positions A and B of FIG. 3. It will be noted that tapes 16c, 16d and 16e are held by the sensing finger at the A position while the tapes 17c, 17d, and 17e are held by the sensing finger at the B position. The effect on the control operation caused by holding tapes 16 and 17 in corresponding positions will be described shortly.

Tapes 16 and 17 are normally held in homepositions shown in FIG. 3 by a bellcrank having an arm 28 (FIG.

1) extending through openings 29 inthe tapes. Another arm 30 on this bellcrank acts against a cam 31 fixed to a shaft 32. A high point on this cam normally holds the bellcrank in a position to locate the tapes so the right the action of the spring elements 25. For rotating the shaft 32 there is provided a conventional spring clutch 33 which is operable to connect this shaft to a continuouslyrotating shaft 34. The clutch 33 includes a helical spring, not shown, which tends to contract into engagement with portions ofthe shafts 32 and34. Fixed toone end of the spring is a member 36 having shoulders 37 at diametrically opposite points. This member turns freely relative to the shaft 34 and is normally held against rotation with the shaft by a pawl 33 engaging one of the shoulders 37. I The other end of'the clutch spring is connected to a member fixed to the shaft 32 and having diametrically opposite shoulders 43. A pawl 41 normally engages one or the other of the shoulders 40 for holding the shaft 32 against rotation in a clockwise direction. With the pawls 38 and 41 engaging the shoulders 37 and 40, respectively, the clutch spring is held expanded so no drive connection is obtained between the shafts 32 and 34. When the pawl 33 is disengaged from the shoulder 37, the clutch spring contracts and effects a driving of the shaft 32 from the shaft 34. If the pawl 38 engages the next shoulder 37, the clutch spring is expanded but shaft 32 continues to turn aslight amount under inertia until the pawl 41 drops in back of one of the shoulders 49 for holding the clutch spring expanded.

Arranged beneath the interposers 6 and extending transversely thereof is a bail 43 having a flange 44 against which a projection 45 on each interposer moves when the latter .is unlatched from the bar 11. The bail 43 rocks about pivot points 46, and connected to one 'of the bail arms at a point below the pivot is a link 48 which is attached to the pawl 38. When any one of the keylevers is actuated to release its interposer from the bar 11, the

interposer is moved rearwardly by its spring element 8 to I swing in a direction for releasing the tapes 16 and'17 so they can move to the right under the action of the spring elements 25 if they are. not held by the sensing finger 14.

As shown hereimmovement of the code tapes 16 determines the positioning of the type head 2 for printing a selected character. The head positioning means may be like that shown and described more in detail in United States Patent 2,919,002 to L. E. Palmer. This mechanism includes a flexibledrive element 52 passing over a pulley 53 on a lever 54 and operatively connected to the type head for rotating the latter. Another flexible drive element 55 passes over a pulley 56 on a lever 57 and is operatively connected to the type head for tilting it varying amounts. A rocking of the levers 54 and 57 is elfected by a bail 58 acting on one or more of several latches 60. Each of the latches is normally in a position to be engaged by the bail as it is rocked downwardly.

Different characters on the type head 2 may be moved into a printing position relative to a platen 61 by drivingthe latche'sdtl in different combinations. The latches 60 may be moved selectively from under the ball 58 by pull rods 62 which are connected, as shown in FIG. 1, to bellcranks 63. One arm 64 ofeach bellcrank extends through a short opening 65 (FIG. 3) in one of the tapes 16 and through long openings 6-6 in all the other tapes 16' as well as the tapes 17. It will be seen that each of the tapes 16 will operate, when moved to the right, to swing one of the bellcranks 63 for moving the associated latch 68 from under the-bail 53. Movement of the other tapes will have no effect on that particular latch.

After the latches 60 have been positioned by the tapes 16, it is necessary that the bail 53 be rocked downwardly for operating any latches remaining under it. This is accomplished by cams, not shown, fixed to a shaft 68 and acting on the bail 58 for moving it downwardly against the action of suitable yielding means. Other cams 69 on the shaft 6% swing a carrier '71? for the type head upwardly to engage it with theplaten and effect printing. Shaft 68 is adapted to be driven, as shown in FIG. 1, by a continuously rotating shaft 72 acting through a spring clutch 73. This clutch is like clutch 33'and is normally held disengaged by pawls 74 and 75 acting on shouldered members 76 and 77. Both shafts 34 and 72 are driven by a belt 78extending over pulleys '79 and 80 on these shafts and driven, in turn, by apulley 81 on a power shaft 82. For engaging clutch 73, the pawl '74 is connected by a pull rod 84 to a bellcrank 85 having an arm 86 extending through an opening 90 in a clutch tape 91 which extends parallel to the tapes 16 and 17 at the rear sides of the latter. right by a spring 92 but is normally held in a left hand home position by a bellcrank 93 acting on the tapethrough means operate to check the positions of the tapes 16 and V 17 for determining whether or not their arrangement is representative of one of the characters to be printed. If

.the arrangement is representative of some character, the clutch tape 91 is permitted to move in a normal manner when it is released by the bellcrank 93 and effect engagement of the clutch 73 to cause a selecting and printing of the character. If the arrangement of the tapes 16 and 17 is not representative of a character, the clutch tape 91 is engaged and held against movement even though it is released by the bellcrank 93.

The means for checking the positions of the tapes 1 6 and 17 include a bail member 98 located below the inter- .posers 6 and supported at a point 99 for pivotal movement. Formed on the member 98 are six spring fingers, numbered 100a to 100 which lie opposite. slots" 101 formed in the lower portions of the tapes 16 and 17. Because of their spring characteristic, any one (or more) of these spring fingers can penetrate the tapes when holes are presented to it regardless of the restriction of movement of the remainderof the fingers. The slots 101 are so formed that movement of either tape 16a or 17a to the right in FIG. 3 will position the left end of theslot to the right of finger 100a so this finger is blocked against movement through the tapes; Movement of either tape 16b or 17b to the right locates a portionof one tape or the other in the path of the finger 10011 for blocking its movement. In a similar manner one or anotherof tapes 16 and 17 will block movement of fingers 1000, 100d, 100e and 100]. The blocking of any one finger can be accomplished only by one of the tapes 16 or the corre As described above, the insertion of the sensing finger on a single interposer through the openings 20 and 21 at a'characterposition on the tapes results in the holding of some tapes 16 while others are permitted to move.

At the same time, the tapes 17 assume positions which Tape 91 is urged to the Assuming that this motion takes place, then the clutch 73 is engaged to drive the'type head for selecting a charare the direct opposite of their corresponding tapes 16. It will be seen that the settings of tapes 16 and 17 for any selected character will result in the blocking of all fingers 100a to 100f against movement. through the slots 101. If interposers at any two or more character positions are inserted simultaneously through the openings 20 and 21, then at least one of the tapes 16 and its corresponding tape 17 will be held against movement. This will permit the corresponding one offingers 100a to 100 to move 107 riding on a cam 108 fixed to the shaft 32. As this shaft rotates, the cam 108 drives thefollower 107 about a pivot point 109 and rocks the bail member 98 in a direction to engage the fingers 100 with the slides. Mounted on the shaft 32 adjacent the cam 108 is another cam 110 acting on a follower 111 which is connected through a link 112 to the bail 43 at a point above its pivot 46. After the interposer 6 has operated to hold the tapes 16 and 17, the cam 110 drives the follower 111 to rock the bail 43 in a counterclockwise direction. .During this time,.theflange ,14 on the bail acts on the projection 45 of the interposer for moving it forwardly until the projecting portion 10 moves from under the plate 11 and is forced upwardly by the spring 12 to latch it against the edge of the plate.

A cycle of operation for the mechanisms described is indicated by the timing diagram of FIG. 4. Shortly after depressing one of the keylevers 1, its'interposer 6 is moved through openings 20 and 21 in the tapes 16 and 17. As the interposer moves toward the tapes it actuates the bail 43 for engaging the clutch 33. As indicated by the diagram, clutch 33-engages at zero time and starts driving the shaft 32. Cam 31 starts rocking the bellcrank arm 28 immediately for releasing the tapes 16 and 17 to move under the action of the spring elements 25 if they are not held by the interposer. About five milliseconds later the bail 98 is rocked by the cam 108 to move the fingers 100a to 100 toward the tapes. This is followed by a releasing of the clutch tape 91 for movement to the right if it is not held by one of the fingers.

acter and printing it. If the clutch tape 91 is held by one of the fingers, then the cam 96 operates again soon after releasing the tape for locking it once more against movement. As soon as this occurs, the bail 98 is rocked by a spring 114 to withdraw the fingers from the tapes 16 and 17. As the clutch member 36 rotates to a position engaging its next shoulder 37 with the pawl 38, the clutch 33 is disengaged but the shaft 32 rotates slightly under inertia until the pawl 41 drops behind the next shoulder 40 and holds the clutch disengaged.

While the keyboard mechanism has been shown and described as a control for a printing element, it will be understood that the tapes 16 could just as well control the selection of punch elements which may be driven by the shaft 68. They could also operate electrical contacts in circuits which may be completed on the rotation of shaft 68 for producing pulses representative of characters corresponding to the keylevers actuated.

While there has been shown and described in this application one form which the invention may assume in practice, it will be understood that it may be modified and embodied in various other forms without departing from the spirit or scope of the appended claims.

What is claimed is:

' 1. A key operated machine comprising, in combination:

a plurality of keylevers; an interposer associated with each of said keylevers; a group of code tapes; and corresponding check tapes movable longitudinally between inoperative and operative positions; openings in said code tapes and said check tapes'in alignment with each other at points opposite said interposers when said tapes are in their inoperative positions, said openings adapted to receive said interposers and being of such length that each of said tapes is either held by an interposer against movement or is .permitted tomove to its operative position, the lengths of the openings in said checktapes being complements of the openings in the corresponding code tapes;

tive positions; means releasably holding said tapes in their inoperative positions; means operating on actuation of 'any one of said keylevers for moving its associated interposer'through the openings opposite it in said -tapes and for releasing said holding means; elements connected to said code tapes and adapted to be selected, by movements of the -.latter, for actuation to produce a function corresponding to any keylever actuated; I clutch controlled means for actuating said selected elements; and means operating after said code tapes and said check tapes have moved for sensing their positions, said sensing means operating to render said clutch controlled means ineffective when the positions of said tapes are not representative of a function for any one of said keylevers. 2. The machine of claim 1 in which said last mentioned means includes: a plurality of sensing fingers; means for engaging said sensing fingers with said tapes after they have moved to their operative positions; openings in said tapes formed in such manner that one or more of said fingers passes through them when one or more of said code tapes and their associated check tapes are held against movement; and means engaged by any one of said sensing fingers on passing through said tapes for rendering said clutch controlled means ineffective. 3. A key operated machine comprising, in combination:

a plurality of keylevers; an interposer associated with each of said keylevers; a plurality of code tapes and corresponding check tapes movable longitudinally between inoperative and operative positions; openings in said code tapes and said check tapes in alignment with each other at points opposite said interposers when said tapes are in their inoperative posi tions, said openings adapted to receive said interposers and being of such length that each of said tapes is either held by an interposer against movement or is permitted to move to its operative position, the lengths of the openings in said check tapes being complements of the openings in the corresponding code tapes; means operating on actuation of any one of said keylevers for moving its associated interposer through the openings opposite it in said tapes; yieldable means tending to move said tapes to their operative positions after an interposer has been moved through openings therein; elements connected to said code tapes and adapted to be selected, by movements of the latter, for actuation means yieldingly urging said tapes toward their operato produce a function corresponding to any keylever actuated;

means operable to actuate said selected elements;

andmeans for sensing the positions assumed by said tapes under the action of said yieldable means, said sensing means acting to prevent operation of said operable means when the positions of said tapes are not representative of a function for any one of said keylevers.

4. The machine of claim 3 including:

a type head operatively connected to said selectable elements and driven by the latter to type characters corresponding to the keylevers actuated.

5. The machine of claim 3 in which said means of actuating said selected elements includes:

a clutch;

means normally latching said clutch in a disengaged position;

means including a clutch control tape which is operable after said code and checktapes have moved for unlatching said clutch, said sensing means includingfingers cooperating with said code tapes and said check tapes; y

openings in said code and check tapes through which one of said fingers may pass when any one of said code tapes and its corresponding check tape are held against movement;

and openings in said clutch control tape for receiving any one of said fingers passing through said code and check tapes, said clutch control tape being held against operation by a sensing finger received withlevers for eifecting movement of said code tapes in a combination representative of the character for the keylever actuated, said operating means also effect-r ing movement of said check tapes as a complement of the code tapes; I

means for sensing the positions of said code and check tapes after they have been moved;

and means controlled by said sensing means for preventing operation of said 'chara cter selection means when the positions of said tapes are not representative of some character.

References Cited in the file of this patent UNITED STATES PATENTS V Sears July 5, 1898 606,944 3,021,937 Seymour Feb. 20, 1962 r 3,045,799

Seymour et al July 24; 1962 

1. A KEY OPERATED MACHINE COMPRISING, IN COMBINATION: A PLURALITY OF KEYLEVERS; AN INTERPOSER ASSOCIATED WITH EACH OF SAID KEYLEVERS; A GROUP OF CODE TAPES; AND CORRESPONDING CHECK TAPES MOVABLE LONGITUDINALLY BETWEEN INOPERATIVE AND OPERATIVE POSITIONS; OPENINGS IN SAID CODE TAPES AND SAID CHECK TAPES IN ALIGNMENT WITH EACH OTHER AT POINTS OPPOSITE SAID INTERPOSERS WHEN SAID TAPES ARE IN THEIR INOPERATIVE POSITIONS, SAID OPENINGS ADAPTED TO RECEIVE SAID INTERPOSERS AND BEING OF SUCH LENGTH THAT EACH OF SAID TAPES IS EITHER HELD BY AN INTERPOSER AGAINST MOVEMENT OR IS PERMITTED TO MOVE TO ITS OPERATIVE POSITION, THE LENGTHS OF THE OPENINGS IN SAID CHECK TAPES BEING COMPLEMENTS OF THE OPENINGS IN THE CORRESPONDING CODE TAPES; MEANS YIELDING URGING SAID TAPES TOWARD THEIR OPERATIVE POSITIONS; MEANS RELEASABLY HOLDING SAID TAPES IN THEIR INOPERATIVE POSITIONS; 